Meter provers and flow providing components provide a known traceable volume to simulate actual operating conditions and to test and verify the performance of a flow meter. Small volume provers (SVP) can be employed in an oil and gas industry to calibrate a flow measurement device employed in a custody transfer, pipe lines, etc. Small volume provers generally include a precisely honed cylinder with sensors to detect the beginning and end of a stroke of a piston. The volume of the stroke can then be employed to verify the volume measured by the device under test.
Conventional small volume provers for calibration of a liquid flow sensor measure a fixed volume, typically by utilizing a pair of fixed position optical slot detectors on the piston of the small volume prover. Such prior art small volume provers can only be employed to verify a fixed volume related to size of the small volume provers such as cylinder diameter and stroke (piston) length. Additionally, a test tank (e.g., seraphin) must have an exact volume matching the size of the small volume prover for verification of accuracy of the small volume prover. Furthermore, if the optical slot detectors are replaced after maintenance, the unit needs to be recalibrated.
Based on the foregoing, it is believed that a need exists for an improved small volume prover apparatus and method for providing variable volume calibration. A need also exists for an improved position sensor for monitoring position and movement of a piston, as described in greater detail herein.